Dom1878 Posted June 11, 2015 Share Posted June 11, 2015 Hi I've had a new sprocket and chain set on for about 5 months and have kept an eye on the tension from time to time. A couple of weeks ago on the way to work it suddenly slackened right off - about 3 inches of play. I stopped in a garage on the way and they tightened it up but said there was a serious tight spot but this should work itself out after a few miles. 2 weeks later and I've just had the chain jump off the rear sprocket twice this morning. Both times at low speed between 1st and 2nd. Could the mechanic have messed anything up when he tightened it or is there any obvious reason for this. I will have to get it to the Yamaha garage in town as I have no tools or jack in my current location? Any help is appreciated. Cheers Link to comment Share on other sites More sharing options...
blackhat250 Posted June 11, 2015 Share Posted June 11, 2015 Wheel must be outa line , [sprockets] how come the sudden slackness, was wheel not tight, /? Link to comment Share on other sites More sharing options...
Moderator Cynic Posted June 11, 2015 Moderator Share Posted June 11, 2015 What make c+s? The chineese have some interesting ideas of what 'quality' means. Link to comment Share on other sites More sharing options...
Dom1878 Posted June 11, 2015 Author Share Posted June 11, 2015 No idea why it suddenly loosened off. I was thinking if the alignment could be out. The chain and sprocket were ordered in and fitted by the Yamaha dealership and have been fine up to now. Will extra weight on the bike cause overstretching of the chain? ie pillion or baggage etc Link to comment Share on other sites More sharing options...
Moderator Cynic Posted June 12, 2015 Moderator Share Posted June 12, 2015 Bad alignment will make the chain jump, thing is chains don't WANT to jump the sprockets. Their very design means they pull themselves onto the sprockets. I have had chains that were absolutely worn to their limit, like 17000 miles (scotoiler) and it stayed on. Slack as a prossies chuff but stayed on. Tight spots don't free off either, the tight spot is something that forms in a chain from use. Something to do with frequency, tension and power transfer effects on the chain. There will always be one and you having a big tight spot, big enough for the chain to jump says adjustment. Unless your packing more weight than the average brit, (according to Yamaha that's about 80Kg) which will affect how you adjust your chain.I'd say the chain adjustment was done wrong at the replacement and now the chain is, well. Knackered really, wouldn't be the first time a garage has done a chain up a little tight so that its right when the owner checks it a few weeks later. Link to comment Share on other sites More sharing options...
Dom1878 Posted June 15, 2015 Author Share Posted June 15, 2015 So to confound this nightmare of a week, in nursing the bike around to the garage at 10mph, the chain and front sprocket ripped itself to pieces cracking the crank case and have been given an £800 rebuild bill. To top this off, Carole Nash have said that FULLY COMP insurance does not cover me. What the hell am I paying for then? Link to comment Share on other sites More sharing options...
slice Posted June 15, 2015 Share Posted June 15, 2015 Well sorry to hear that, bloody hell when it rains it pours as they say. Your insurance covers you for "accidents" not mechanical breakdowns, never has and never will I'm afraid. Your best bet is to use the net to find the parts yourself and even fit them cos half or more of that bill you got was labour. Look on EBAY and GUMTREE to see if their are any bikes like yours for sale that you can cannibalise or just look for the parts you need rather than a whole bike, would work out much cheaper than buying new from Yamaha, just as an aside I have just replaced the plastic retainers that hold the panels on my bike, Yamaha price is £6 each my local car factors I got 10 for a pound, exact same thing! Link to comment Share on other sites More sharing options...
blackhat250 Posted June 15, 2015 Share Posted June 15, 2015 FKn ell" , how long ago were they fitted ? [ new that is] Link to comment Share on other sites More sharing options...
Moderator Cynic Posted June 15, 2015 Moderator Share Posted June 15, 2015 Its why i don't trust dealers. Somebody's innatention couple of months ago has cost you big time. Link to comment Share on other sites More sharing options...
Simon46 Posted June 15, 2015 Share Posted June 15, 2015 I would go back to dealers. A 125 can't ruin a chain in 5 months. Link to comment Share on other sites More sharing options...
KevtheRev Posted June 16, 2015 Share Posted June 16, 2015 A 125 can ruin a chain and sprockets in a few hours depending on the cackhandedness or inattention of the person fitting it . 1 Link to comment Share on other sites More sharing options...
Dom1878 Posted June 16, 2015 Author Share Posted June 16, 2015 They had been fine up till now. Fitted in February by Yamaha in Worthing, authentic parts. As I was working away and had no tools or jack the other week it was a quick £10 job at a bike garage. I remember him not taking much notice of the adjustment marks on the side and wondered if he had done it evenly. Possibly not. Situation now has a minor silver lining as it is the bolt hole for the engine casing just above (to the left) the front sprocket that sheared. Have spoken to an alloy specialist who thinks he can build it back up and retap it. Yamaha are happy to proceed with just replacing c&s set if I get this done well. Fingers crossed as there is still only 9000 on the clock and she runs lovely. 2 Link to comment Share on other sites More sharing options...
Moderator Cynic Posted June 16, 2015 Moderator Share Posted June 16, 2015 The other week. Sounds like that tenner was an expensive bargain. Link to comment Share on other sites More sharing options...
Grouch Posted June 16, 2015 Share Posted June 16, 2015 through my experience 125 chain and sprockets seem to wear down quicker. The chain especially seems to need to be tightened every week. Even after cleaning and lubing I still need a new set every 6k miles. Link to comment Share on other sites More sharing options...
KevtheRev Posted June 17, 2015 Share Posted June 17, 2015 Hope you get it sorted mate . Btw , you dont need a jack to adjust/lube your chain . All you need is an adjustable spanner that'll fit the spindle nut and a 10/12 mm open spanner for the adjusters . Shouldn't cost more than a fiver for both . My last word on this , - SCOTTOILER . Link to comment Share on other sites More sharing options...
Moderator Cynic Posted June 17, 2015 Moderator Share Posted June 17, 2015 Meh. Not sure on scottoilers for little bikes. They don't have the more stable vacume of bigger engines. Got one on my TDR and it either drenches everything or you get odd drops. Prob down to it running flatsides. Link to comment Share on other sites More sharing options...
KevtheRev Posted June 17, 2015 Share Posted June 17, 2015 Meh. Not sure on scottoilers for little bikes. They don't have the more stable vacume of bigger engines. Got one on my TDR and it either drenches everything or you get odd drops. Prob down to it running flatsides. Maybe it's banjaxed , lol . Or the flatslides could be a bit turbulent for it . Does the TDR have a vacuum operated fuel tap ? Maybe you'd get a steadier vacuum there? I wonder are there any vacuum-less drip feed oilers available that might suit ?? Link to comment Share on other sites More sharing options...
finnerz89 Posted June 17, 2015 Share Posted June 17, 2015 I think all the newer scottoilers are electronic Link to comment Share on other sites More sharing options...
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